Q: How do I find out how many shares of stock a company has outstanding? Can you use Walgreen (WAG) as an example?

A: Many investors think about just one thing: a stock's share price.

When you log into your portfolio, you usually just want to know the price and whether it was up or down during the day. And knowing the stock price is sufficient most of the time.

But investors who want to dig a little deeper also pay attention to a company's shares outstanding. This tells you how much of a company you own when you buy a share of stock.

Think of a pie being served at a party. If you ask the host for one slice, that doesn't indicate how much pie you will get. If the pie is cut into 20 pieces, a slice is going to be a sliver. If the pie is sliced into four pieces, a slice can be a meal.

Shares outstanding brings the same logic to stock. When companies have hundreds of millions of shares outstanding, your ownership can be insignificant. And your stake can be watered down if a company issues additional shares.

That's why many professional investors consider both a company's share price and number of shares outstanding when evaluating a stock. You can put a price tag on the company by multiplying the number of shares outstanding by the share price. That gives you the company's market value or market capitalization.

So, where can you find a company's number of shares outstanding? That is available on all the quarterly (10-Q) and annual (10-K) regulatory filings made by companies to the Securities and Exchange Commission.

But there is an easier way. Just log onto money.usatoday.com and scroll down a bit until you see the "Get a quote" box on the left side of the screen. Enter the name or ticker symbol of the stock you're interested in, which in this example, will be WAG for Walgreen. Click the Go button.

You'll see a screen filled with information about the stock. Below the USA TODAY Stock Meter, you'll see the company's shares outstanding, where it says Shares Out. And that number for Walgreen is 992.4 million. If you multiply 992.4 million by the stock price, you'll get the stock's market value, or Market Cap, which is on the next line. Right now it's about $34 billion.

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